Currently, FTTx has become very popular in an access domain because of its advantages such as high bandwidth and a long distance, and particularly, an optical access technology characterized by point-to-multipoint transmission, that is, a passive optical network (passive optical network, PON) has gained the attention of the industry. Compared with point-to-point optical access, a PON central office uses a feeder fiber, which can be divided into tens of or even more fibers, to connect to users, and network construction costs are greatly reduced. The PON is a most economical and effective technical means of the FTTx. At present, a PON technology mainly includes an Ethernet passive optical network (Ethernet Passive Optical Network, EPON), a gigabit passive optical network (Gigabit Passive Optical Network, GPON), and the like, and a main difference between the EPON and the GPON lies in that different Layer 2 technologies are used.
With the arrival of an era of cloud computing, bandwidth and services of an access network increase rapidly, and problems and challenges that a conventional PON faces are increasingly prominent. The conventional PON is designed by using broadband access of residential users as the core, and a bandwidth statistical multiplexing gain brought by Time Division Multiple Access (TDMA) and a large port convergence ratio are core technical advantages of the conventional PON. However, when a TDMA channel is applied to a service scenario other than residential broadband access, there are many limitations and disadvantages. For example, for enterprise access, a current manner of sharing bandwidth in a time division multiplexing (Time-Division Multiplexing, TDM) manner causes security and reliability problems or the like to the enterprise access; for another example, a low delay of wireless backhaul, precise time synchronization, and large exclusive bandwidth is a key requirement, and therefore, a Time Division Multiple Access technology is not suitable to be used.
For the problems and challenges that the foregoing conventional PON network faces, a solution provided by the prior art is to use different systems separately for different application scenarios. For example, for residential users, a TDM-PON (for example, a GPON or an EPON) is used; for wireless backhaul, a WDM-PON with a low delay is used, or, two systems are stacked in a wavelength superposition manner, to deal with scenarios of residential users and wireless backhaul.
However, in the foregoing solution provided by the prior art, no matter which manner is used, different systems are required to deal with different scenarios, which not only increases investment costs, but also causes complex operation and maintenance.